Technically, no. Flare is a minimum of 850~MP. You don't need all your MP to use it, but you CAN use all your MP to use it.
Also, Mycow8me, as far as I'm concerned, healers should be DPSing as long as their heals aren't required for that specific GCD. If you believe that they shouldn't be DPSing and that Cleric needs to go and MP costs need to be boosted, that's fine. You can have that mindset, even if it's inane to state that MP consumption should be high for DPS spells. Imagine running out of MP in the middle of a story duty and failing because you can neither heal yourself nor deal damage to the enemy... that would be broken.
Just take a second and think about what you're talking about instead of just throwing out ideas without thinking of repercussions.